习题课(2)
完形填空
A
London's River Thames has twentyseven bridges. Tower Bridge, the first bridge over the Thames as you travel towards London from the sea, is the__1__of them all.
The thing that is surprising about __2__is that it opens in the middle. It does this to let the big ships__3__to the Pool of London. If you are__4__enough to see the bridge with its two opening arms high in the air, you will never forget it.
